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Hovercraft model
- FAQ -

Why a hovercraft model ?

How to design such a model ?

For doing what ?

Why Sevtec ?

Is this model a Sevtec ?


Advantages of a model for testing

I don't have much money, but I find your model interesting

What you can find on Internet

Why a hovercraft model ?

I'm interested in hovercraft from some years now, and following the Internet trails at random, I've gone through interesting sites, among them the Sevtec site. One year (or two, or more) after this first visit, a new visit have increase my interest, and I've began to think to realise a full size hovercraft.

After serious thinking, and after having seen the problem on numerous sides, i concluded that, even if suspending the hull below the motorcycle trailer, which is itself suspended to the ceiling, it was impossible to find sufficient room in my tiny garage, where there is already the workshop, the motorcycle, and sometimes the car...

Moreover, i was intending to realize a model derived from a Sevtec, but with different materials (in wood). The idea to make a model was interesting to develop such a prototype.

That was also an opportunity to began in radio model, activity where i was interested from long, but had never take the time to start.

How to design such a model ?

An attentive reading of Sevtec site and nearly all Sevtec and others models builder sites have driven me to realise a wood-epoxy hull, instead of the polyurethane/polyester hull of Sevtecs. While some Sevtecs have been realised in wood, their structure is not well adapted to this material.

So, I've made my own design with a method i'm used to.

I make drawings on computer, print the result on thick paper, cut with scissors, and assemble the parts by gluing,

After more than fourteen different design (see photos) and numerous hours, I've arrived to something which was pleasing me. After that, I've bought the Sevtec Scout and Vanguard drawings, to get the core thing of an hovercraft, the skirt design.

I've read carefully those crowded drawings.

The propeller stand was not pleasing me, because it was in steel, subject to important corrosion, as you can seen on a lot of photos. Also, it was looking a bit weak, which seems a wrong assumption, given the experience of builders.

Though, this stand is very well designed, and it needed me a lot of hours to design a good alternative with reasonable weight.

The drawings I've made for this model were designed to be a reduced model of full scale hovercraft. They have been adapted for a radio model, especially for motor and propeller stand fixing, very different from a full size craft, where there is a piston engine, and where safety is much more involved.

For doing what ?

Time expensed in designing, drafting, realising, testing this model is probably higher than the time needed to build a full scale craft from plans.

But my preferred activity is design, so why not ?

Why Sevtec ?

I've read carefully the majority of what you can find on the Internet about pleasure hovercrafts, and the quality of Sevtec design seems me much better than other designs. I've been particularly impressed by 'explorer' series. That idea to install lifting fans in 'wrong' direction at craft aft, while surprising, is remarkable when you closely look the design.

On full scale crafts, one engine simplicity with 'mule drive' transmission is evident. Low speed high diameter propeller give an evident increase of efficiency for whoever have some knowledge's about propellers and their history. The only drawback of such a design, say, increased forward momentum, is elegantly solved by the skirt compartment system.

Material economy and simplicity of engine stand is difficult to improve (Though I've tried to, you will be judge of the result)

Is this model a Sevtec ?

General philosophy, look, working are comparable to a Sevtec, as I can judge on films, because i've never seen nor try one 'in real'.

Anyway, there is no common dimension, and hull structure philosophy is fundamentally different from a Sevtec, not only regarding the material. I've designed the hull before boughting Sevtec drawings, but based upon main dimensions given on the Internet.

Skirt is double fore compartment, requested on radio model, because there is no 'body language' to pilot the model. Its design is closely derived from a Vanguard skirt, with some simplifications, and modifications to adapt to the hull structure.


I've encounter difficulties to inflate fore compartments, and to adjust the skirt in the front part and in partition skirt.

Advantages of a model for testing

I've proceed to numerous modifications during construction. If the building of a reduced model is often nearly as long as the full scale model, it's modification tend to be easier.

The best and most instructive point, though, is to test the model on a glass, and to look the skirt from bottom.

I don't have much money, but I find your model interesting

No, this model is not for beginners or people lacking money. it quite performing, but it's complex and costly (it's a bimotor), and the radio programmation is quite subtle.
To make experiences with low cost and simple hovercrafts, my advice is to go there:

What you can find on Internet

On forum 'alt.rec.hovercraft', you can find a lot of information's, and lengthy battles on various technical subjects. Barry Palmer (Sevtec), is very present on this forum. His speeches self defending and a behaviour which may appear sometimes arrogant have alienated him some of his readers. Though, you must not be fooled, he is one of those who have the biggest experience in this area, and the quality of his design seems me beyond question.

The aim of his production is pleasure or service crafts, which is not everyone objective. If you wish to compete, you must find others design.

If design is good, the drawing quality is another story. Drawings are a little scarce and sometimes not easy to interpret. Fan guard details are way insufficient, and I think this is the reason why we can found a big variety of designs..

Moreover, theses drawings are in US units (nothing really surprising...), and non-US builders are obliged first to translate units, which is a big waste of time. I've redraw the Vanguard skirt with CAD tool in US units and have scaled it in more civilised units to do the job. I esteem it haven't taken me more time than to manually translate on drawings.
If you are more or less used to CAD tools, this is the way to go. Plus, it helps very much for elaborating a placing on fabric or sheets. And it avoid mistakes. And it helps to make any scale models, also...

Information's on other reduced models ?

Yahoo have created a mailList on hovercrafts models.
To inscribe yourself : rchovercraft-subscribe@yahoogroups.com

Few sites on this matter, but find here some links.